The invention relates to fluid distribution valves of the type which sequentially open a plurality of outlet ports of a closed chamber that receives pressurized fluid via an inlet port, and more particularly to an improved distribution valve having a high efficiency impeller, gear assembly, and sequential valve actuation mechanism.
Multi-outlet fluid distribution valves that receive fluid under high pressure through an inlet port and distribute the fluid, one port at a time, through sequential outlet ports are commonly used in self-cleaning swimming pool systems. In such systems, swimming pool water is pumped at high pressure, typically roughly twenty to forty pounds per square inch, into the inlet port of the distribution valve. The outlet ports are coupled by lengths of PVC pipe to spaced "cleaning heads" that are installed in the bottom of the swimming pool surface and eject rotary jets of high pressure water along the bottom of the pool to effectively sweep circular areas around each cleaning head. For example, a fluid distribution valve bearing some resemblance to the one disclosed in U.S. Pat. 3,405,733, issued to K. W. Hansen on Oct. 15, 1968 and assigned to the present assignee using the basic concept of a manifold with a rotary, gear and impeller driven valve, has been used for this purpose. Design disclosed therein has been quite workable and, in fact, quite a number of similar valves, modified in various respects have been introduced to the market, and the basic design of that distribution valve has proven to be quite difficult to improve upon. Nevertheless, experience in the swimming pool industry has indicated that there is a need for improved implementation of the subject distribution valve. Chemicals commonly used in swimming pool water have been found to gradually weaken and degrade some of the plastic and metal components that have been used in prior distribution valves. Some of the prior distribution valves have not been reliable in the presence of substantial variations in the inlet pressure, or at low water flow rates. In some cases, build-up of debris on some of the components of prior distribution valves has interferred with their proper operation, increasing maintenance costs, especially when the chemical balance of the swimming pool water has not been properly maintained.
Accordingly, it is an object of the invention to provide an improved distribution valve that operates reliably at low inlet pressures and low fluid flow rates, is more resistant to degradation caused by swimming pool chemicals, and requires less maintenance than prior distribution valves.